I was wondering if there are audio usb libraries or references for the SAM3U-EK laying somewhere around here. I've tried looking at the atmel website but I haven't had any luck yet. The only documentation about audio usb 2.0 I've had so far is from the usb.org website.

In terms of code, I've written up the descriptors and class requests for audio usb 2.0 so far. I've started writing setup and other such functions but it would be awesome if any of you knew some documentation or could help me out here!

euphoricnoise wrote:I was wondering if there are audio usb libraries or references for the SAM3U-EK laying somewhere around here. I've tried looking at the atmel website but I haven't had any luck yet. The only documentation about audio usb 2.0 I've had so far is from the usb.org website.

In terms of code, I've written up the descriptors and class requests for audio usb 2.0 so far. I've started writing setup and other such functions but it would be awesome if any of you knew some documentation or could help me out here!

Hi so I've made some progress and now my computer detects my evaluation board (SAM3U-EK) as a composite USB device (audio and HID!). However, there is an error with the Audio Device part. It says the device cannot start.

Can anyone help/give me a clue why it is not starting up properly? Maybe it's the way I'm writing the descriptors? Any usb audio experts out there?

euphoricnoise wrote:Hi so I've made some progress and now my computer detects my evaluation board (SAM3U-EK) as a composite USB device (audio and HID!). However, there is an error with the Audio Device part. It says the device cannot start.

Can anyone help/give me a clue why it is not starting up properly? Maybe it's the way I'm writing the descriptors? Any usb audio experts out there?

Does it enumerate as an Audio Class 2.0 or 1.0 device? The descriptors for the former are more involved than for the latter.

I'm afraid I do not have a bus analyzer. As this is my first time working with USB Protocol, I am not sure what I need to troubleshoot properly.

EDIT: I've been using a free usb bus monitor software and I've noticed that my terminal, feature unit descriptors are not being detected so I'll look more into it and let you know later

EDIT2: So I've switched over to USB Audio 1.0 (since it was easier to understand and test it) and I've got the following (below). Only problem is that it's still doesn't function properly. Any ideas? Am I still not enumerating correctly?

euphoricnoise wrote:EDIT2: So I've switched over to USB Audio 1.0 (since it was easier to understand and test it) and I've got the following (below). Only problem is that it's still doesn't function properly. Any ideas? Am I still not enumerating correctly?

Andy Peters wrote:
Why a mouse/boot interface? That's a rather special interface; instead, do some kind of user-defined report format.

I'll dig up descriptors later. I think there are things missing from yours, but I don't have any references here to verify against.

I wanted to test some things later using a composite HID/audio device. But if you could verify the descriptors with me because so far I know I need:
- AudioControl Descriptor (containing Terminal, Feature Unit descriptors)
- 2 AudioStreaming Descriptors (One input and one output stream)

UPDATE: Looks like I finally got it working. It was actually a problem with the terminal type I was setting it to. In my own confusion, I had set the terminal types in the opposite direction and it wasn't able to run from there. I am working on connecting the usb stream data to an I2S bus now. Will let you guys know where I end up.

did you finished your project? I have a SAM3U-EK since 3 years, but never used it (no time, other projects). Now I want to start USB audio (Class 1 and 2) and just wondering if I may get some tips how to start.
AFS does not supply a USB audio class at all? Should I use it anyway and writing my own Class? Or do you have any code you might share?

did you finished your project? I have a SAM3U-EK since 3 years, but never used it (no time, other projects). Now I want to start USB audio (Class 1 and 2) and just wondering if I may get some tips how to start.
AFS does not supply a USB audio class at all? Should I use it anyway and writing my own Class? Or do you have any code you might share?

Thanks!

Hey thorsten, I never did manage to make it work. The input was always distorted/a lot of jitter. Output was always fine as far as I could tell. Atmel gave me a couple of unfinished files that I ended up fixing (it was VERY broken and they even told me it would only work with Class 1) and it still didn't work. They even suggested me to overclock the chip which isn't something I wanted to do in the first place... Honestly it seems like it's just not worth to build USB Audio for the SAM3U. Obviously the SAM3U is a nice cost-effective chip but not for USB Audio. I'm hoping someone here will prove me wrong but its been almost 3 years since I started asking on the forum and no one really had a real solution from what I could tell.

With that in mind, if you wish to continue with the SAM3U for USB audio... good luck and may God play in your favor lol

Hello euphoricnoise, I am trying to code a USB audio device class 1 or 2 on a SAM G55, there is not much information about it on the web and I am kind of lost in this so I was wondering if you could share some of your code ?